Pretty much what the title says. DES was suspected of having one, but I couldn't imagine what it could possibly look like if only the NSA knew how to use it. Dual_EC_DRBG's backdoor is asymmetric, but ...

I'm attempting to find a client/server authentication protocol that allows the client and server to authenticate each other when the client doesn't know the server secret but does have a sensitive key ...

I am designing a distributed system, composed by a set of physically distributed embedded devices (8 bit cores with less than 1 KB of RAM). The devices need to be able to authenticate the originator ...

Some months ago I found in some paper that we cannot compare symmetric algorithm with asymmetric algorithm based on the key length and more important we cannot compare asymmetric algorithm using only ...

I know using homebrew encryption can be very dangerous as it is very likely to have many flaws in its design. The following concept is just for learning purpose in case anybody is getting red flags ...

To obfuscate data I made up this method on the spot without planning since the goal wasn't real encryption.
At first I though this cannot be real encryption but after revisiting the code and reading ...

If we have a light weight block cipher where the block length is different than the key length. Let's say the block has a length of 64 bits while the key is 80 bits.
For an attack to be successful, ...

I work on an exercise and I have to study functions as : $ f : \mathbb{F}_q \rightarrow \mathbb{F}_q$ with $q = 2^n$ which can define a S-Box for SP-Networks.
There is a question that I can't answer ...

If one wants to keep the receiver's name non encrypted, but it also appears in the encrypted message - will it leak information? (other than the receiver's name, of course.)
Let's assume a "bad" case ...

I know as programming languages C and java , and I know that java is slow so for this reason it is not suitable for cryptography applications espacially low level programming (manipulating bits) , so ...

Propose a symmetric key based crypto-system for implementing a secure email system. This system is based on AES and CCA secure.
Suppose that you have to encrypt a large message and that this message ...

In this scheme, a 256 bit key is split into two 128 bit sub-keys. Message blocks are 256 bits and are also split into two sub-blocks. Before encryption, each sub-block is xor'd with it's partner and ...

We have ciphers that handle small amounts of entropy, such as a 256 bit key for AES; and we have one time pads for enciphering 1:1 entropy, such as a 1GB key for a 1GB file if you could ever harvest ...

I need to store encrypted files on a hard disk. The actual code side is not important for me now (I plan to use C# and AES-GCM encryption from Bouncy Castle library, please tell me if you think that's ...

In SSL/TLS, we use symmetric and asymmetric keys to encrypt the data. Does that mean that the keys are used to encrypt the data (preserve the integrity) or provide a secure channel for the data to be ...

I have just found a way to crack AES-128 in a reasonable time (1-2 days). How do I publish and prove this? I remember reading about lots of people who cracked DES and other ciphers but how did they ...

in short I'm learning GUI programming in python and thought it could be interesting to make a small GUI for symmetric encryption. Not being mad/mathematical/experienced (take your pick) enough to try ...

I'm trying to verify the claim of paper Improved Algebraic Fault Analysis: A Case Study on Piccolo and with Applications to other
Lightweight Block Ciphers about the numbers of equations in algebraic ...

Unbalanced Feistel networks can be homogenous (F-function identical in each round), or they can be heterogeneous (F-function not always identical in each round).
The advantage of heterogeneous UFNs ...

Using a symmetric encryption algorithm $E$ on a message $M$, users usually send $E(M)$ to the recipient and then the recipient will compute $E^{-1}(E(M))=M$ to retrieve the message. For what symmetric ...